Two Island contractors involved in solar energy technology, Philip Forest and Tim Twombly, recently received special certification from the North American Board of Certified Energy Practitioners (NABCEP).

NABCEP is the national certification organization for professional installers in the field of renewable energy. According to its website, NABCEP develops voluntary national certification programs with a goal to promote renewable energy, give value to practitioners, promote worker safety and skill, and promote consumer confidence. Applicants must satisfy eligibility requirements established by the NABCEP board of directors and pass a certification exam.

Mr. Forest, who works in energy design and installation as a co-owner of South Mountain Company in West Tisbury, earned certification as a solar photovoltaic (PV) installer.

Mr. Twombly is the owner of SunWaterMV in West Tisbury, which specializes in an alternative technology that utilizes evacuated tube solar thermal systems. He achieved certification as a solar thermal installer.

Mr. Forest and Mr. Twombly currently are the only two NABCEP certified contractors on Martha’s Vineyard, out of a total of 51 in Massachusetts, according to the organization’s website.